My First Circuit
As you can see God spoke and there was LIGHT!
I'm trying to get the circuit thing down. I can code all day long but this electronic stuff is tricky...
Once I get it down pat I'll post some walkthoughs so other people like me who lack the electronics background can get stuff going easier. I won't post all my minor successes, but I did do a jig when the little light went on. My Picaxe stuff shipped today so I won't post more until I have motors and wheels moving ;)
The journey of a thousand robots begins with a single LED.
@ Fri, 2008-05-02 00:55
My code looks like spagetti
My code looks like spagetti and my solder looks like chicken splatter,
who's gonna team up with me?
GroG
@ Fri, 2008-05-02 01:12
lolz.. lets make a
@ Fri, 2008-05-02 06:57
Brilliant !You just gave me
Brilliant !
You just gave me a great idea for a new project ! OSRC Open Source Robot Cookbook
mmmm ... hungry already - I will continue to update it - feel free to add or change anything when you want..
Yum.
@ Fri, 2008-05-02 09:39
hehe, go on, i'm with you
@ Thu, 2008-05-01 23:54
I can build but not code...
We should team up! I solder like a master and can build anything -metal or wood... I code like shit though...
www.rocketbrandcustom.com baby!!
@ Thu, 2008-05-01 22:13
I ve got no idea how to use
@ Thu, 2008-05-01 22:56
How to select the correct resistence
to limit the corrent that pass by the led, just do V = R I
I = V / R
i sugest 15mA, so:
15mA = V / R
you know the voltage that you aplly, 5V or 9V, or something.. so just need know the resistor to limit it, so:
R = V / 15 mA
if V = 5V, 5/15 = 0,333(3) so use a 330 Ohm resistence
if V = 9V, 9/15 = 0,6 so use a 600 Ohm resistece.. if you can't find one use somthing close to it value.. does not to be the exactly value.
do the same to other voltages that you aplly.
Hope i helped you to understand it.
TigPT
Tiago Rodrigues
@ Fri, 2008-05-02 11:08
Just remember to do the
Just remember to do the calculations in compatible units :-). If you use milli-amperes like in your example the result will be in kilo-ohms.
I always do calculations using volts, amperes and ohms (known as SI-units ... no milli-, kilo- or mega- etc). Then you will get
R = 5 V / 0.015 A = 333.33... ohms
TigPT, you seem to know a great deal about all this electronics stuff. Are you studying electronics or something like that?
- Jimmy
@ Fri, 2008-05-02 13:29
Voltage drop
Aren't you supposed to use the supply voltage minus the forward voltage drop in the equation? Like:
R = (Vs-Vf)/I. The forward voltage dropdiffers from LED to LED, so consult your datasheet. I found a table on the net somewhere, that I use as a guideline:
Infrared 0,7 - 1,5 V
Red 1,8 V
Yellow 2 V
Green 2,2 V
Blue 3 V
White / Ultraviolet 3,3 - 3,6 V
So, to power a red LED with 20mA from a 5V source, the equation is: R=(5-1.8)/0.020=160ohm.
Which also means that you can't power a yellow LED with a 1.5V battery, because your supply voltage must be higher than the forward voltage drop.
@ Fri, 2008-05-02 13:45
think the zenner difrence